function
setActiveStyleSheet (title)
{
  var i, a, main;
  for (i = 0; (a = document.getElementsByTagName ("link")[i]); i++) {
    if (a.getAttribute ("rel").indexOf ("style") != -1
	&& a.getAttribute ("title")) {
      a.disabled = true;
      if (a.getAttribute ("title") == title)
	a.disabled = false;
    }
  }
}

function
getActiveStyleSheet ()
{
  var i, a;
  for (i = 0; (a = document.getElementsByTagName ("link")[i]); i++) {
    if (a.getAttribute ("rel").indexOf ("style") != -1
	&& a.getAttribute ("title") && !a.disabled)
      return a.getAttribute ("title");
  }
  return null;
}

function
getPreferredStyleSheet ()
{
  var i, a;
  for (i = 0; (a = document.getElementsByTagName ("link")[i]); i++) {
    if (a.getAttribute ("rel").indexOf ("style") != -1
	&& a.getAttribute ("rel").indexOf ("alt") == -1
	&& a.getAttribute ("title"))
      return a.getAttribute ("title");
  }
  return null;
}

function
createCookie (name, value, days)
{
  if (days) {
    var date = new Date ();
    date.setTime (date.getTime () + (days * 24 * 60 * 60 * 1000));
    var expires = "; expires=" + date.toGMTString ();
  }
  else
    expires = "";
  document.cookie = name + "=" + value + expires + "; path=/";
}

function
readCookie (name)
{
  var nameEQ = name + "=";
  var ca = document.cookie.split (';');
  for (var i = 0; i < ca.length; i++) {
    var c = ca[i];
    while (c.charAt (0) == ' ')
      c = c.substring (1, c.length);
    if (c.indexOf (nameEQ) == 0)
      return c.substring (nameEQ.length, c.length);
  }
  return null;
}

window.onload = function (e)
{
  var cookie = readCookie ("style");
  var title = cookie ? cookie : getPreferredStyleSheet ();
  setActiveStyleSheet (title);
}

window.onunload = function (e)
{
  var title = getActiveStyleSheet ();
  createCookie ("style", title, 365);
}

var cookie = readCookie ("style");
var title = cookie ? cookie : getPreferredStyleSheet ();
setActiveStyleSheet (title);